- 124 -
SR-LEDW/SR-UL2/SR-UL1R/SR-3AR
Mathematical Formulas
The following formulas are applied by the SR-LEDW/SR-UL2/SR-UL1R/SR-3AR for each data.
Spectral radiance Le (
)
samp
ref
ref
samp
D
D
L
)
(
L
[ W / sr
m
2
nm ]
L
samp
(
):
Spectral radiance of the object [W/ sr
m
2
nm]
L
ref
(
):
Spectral radiance of the perfect reflecting diffuser under standard light A
100
lux [W/ sr
m
2
nm]
D
ref
(
):
Output of the photoelectric element when measuring the perfect reflecting
diffuser under standard light A 100
lux
D
samp
(
):
Output of the photoelectric element when measuring the object.
Radiance Le
2
1
samp
L
Le
1 :
Measuring start wavelength 380 nm
2 :
Measuring end wavelength 780 nm
:
=1
Tristimulus values X, Y, Z Luminance Lv
Observation visual field 2°
samp
2
1
L
x
K
X
samp
2
1
v
L
y
K
Y
L
samp
2
1
L
z
K
Z
¯
x (
), ¯
y (
), ¯
z (
) : Color matching functions in CIE 1931 standard colorimetric system
K
: Parameter 683 lm/W
1
: Measuring start wavelength 380 nm
2
: Measuring end wavelength 780 nm
:
= 1
